Radiation Exposure, Training, and Safety in Cardiology

Exposure to ionizing radiation is an inherent occupational health hazard in clinical cardiology. Health risks have been reported previously, including predilection to cancer. In addition, orthopedic injury due to prolonged wearing of heavy protective lead aprons, which are mandatory to reduce radiation risk, have been extensively documented. Cardiology as a specialty has grown with rising volumes of increasingly complex procedures. This includes electrophysiological, coronary, and structural intervention, advanced heart failure/transplant management, and diagnostic imaging. Both the operator as well imaging specialists are exposed to radiation, particularly in structural interventions where interventional cardiologists and structural imagers work closely. Increasingly, women interested in cardiology may deselect the field due to radiation concerns. This expert document highlights the risks of radiation exposure in cardiology, including practical tips within various subspecialty fields such as interventional/structural cardiology, electrophysiology, imaging, advanced heart failure, and pediatric cardiology.

Practical guidance to reduce radiation exposure in electrophysiology applying ultra low-dose protocols: a European Heart Rhythm Association review

Interventional electrophysiology offers a great variety of treatment options to patients suffering from symptomatic cardiac arrhythmia. Catheter ablation of supraventricular and ventricular tachycardia has globally evolved a cornerstone in modern arrhythmia management. Complex interventional electrophysiological procedures engaging multiple ablation tools have been developed over the past decades. Fluoroscopy enabled interventional electrophysiologist throughout the years to gain profound knowledge on intracardiac anatomy and catheter movement inside the cardiac cavities and hence develop specific ablation approaches. However, the application of X-ray technologies imposes serious health risks to patients and operators. To reduce the use of fluoroscopy during interventional electrophysiological procedures to the possibly lowest degree and to establish an optimal protection of patients and operators in cases of fluoroscopy is the main goal of modern radiation management. The present manuscript gives an overview of possible strategies of fluoroscopy reduction and specific radiation protection strategies.

Radiation exposure during cardiac device implantation: Lessons learned from a multicenter registry

BACKGROUND

Little data are available about radiation exposure during cardiac electrical device implantation, and no dose reference levels have been published. This multicenter, prospective, observational study assesses patient and staff radiation exposure during cardiac device implantations, and aims at defining dose reference levels.

METHODS

Patient demographic, procedural, and radiation data were obtained for 657 procedures from nine institutions. Physician and staff exposure were measured using real-time dosimeters worn beneath and above lead apron. Statistical analysis included fluoroscopy time (FT), dose-area product (DAP), and DAP adjusted for FT and body mass index.

RESULTS

Pacemakers and cardioverter defibrillators were implanted in 481 and 176 patients, respectively. Of these, 152 were treated with cardiac resynchronization therapy (CRT). Median FTs were 837s (interquartile range [IQR]: 480-1323), 117s (IQR: 69-209), and 101s (IQR: 58-162), and median DAPs were 1410 (IQR: 807-2601), 150 (IQR: 72-338), and 129 (IQR: 72-332) cGy.cm² for biventricular, dual chamber, and ventricular device implantation, respectively. Dose reference levels correspond to the third quartile values. During CRT, higher exposure was observed with four X-ray systems than with the two newer and customizable ones (adjusted DAP of 0.90 [IQR: 0.26-1.01] and 0.29 [IQR: 0.23-0.39], respectively; P < .001).

CONCLUSION

Based on real-life measurements, this multicenter registry provides dose reference levels and may help centers assess radiation exposure. Although biventricular device implantation was responsible for the highest radiation exposure, FT was meaningfully shortened compared to previously reported values. For a same FT, the use of new generators and custom settings has significantly reduced DAP.

Impact of cardiac resynchronisation therapy on cardiologists' exposure to radiation during implantation of pacemakers and implantable cardioverter-defibrillators

Cardiologists are among the health professionals that are most exposed to ionizing radiation, but there is no recent study quantifying overexposure of physicians during cardiac resynchronisation therapy (CRT) procedures compared to 'classical' implantation of pacemakers (PMs) or implantable cardioverter-defibrillators (ICDs). We aimed to measure and compare operator exposure to radiation during implantation of PM and ICD with or without CRT. The study population comprised all PMs and ICDs implanted in a large referral centre over a six months period. The endpoint was operator radiation exposure, assessed using a personal electronic dosimeter located on operator's chest. In total, 169 PM/ICD implantations were analysed, 19 of which included CRT. Compared with 'classical' implantation, cardiologist radiation exposure was 9-fold greater during CRT procedures (p < 0.001). Physician exposure was related to dose-area product (R² = 0.21 during 'classical' implantations and R² = 0.57 during CRT procedures). Our study shows that cardiologists' exposure to radiation during CRT implantation was 9-fold greater than during procedures without CRT.

Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures

Despite the advent of non-fluoroscopic technology, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies over ablation interventions to device implantation. Moreover, many patients receive additional X-ray imaging, such as cardiac computed tomography and others. More and more complex procedures have the risk to increase the radiation exposure, both for the patients and the operators. The professional lifetime attributable excess cancer risk may be around 1 in 100 for the operators, the same as for a patient undergoing repetitive complex procedures. Moreover, recent reports have also hinted at an excess risk of brain tumours among interventional cardiologists. Apart from evaluating the need for and justifying the use of radiation to assist their procedures, physicians have to continuously explore ways to reduce the radiation exposure. After an introduction on how to quantify the radiation exposure and defining its current magnitude in electrophysiology compared with the other sources of radiation, this position paper wants to offer some very practical advice on how to reduce exposure to patients and staff. The text describes how customization of the X-ray system, workflow adaptations, and shielding measures can be implemented in the cath lab. The potential and the pitfalls of different non-fluoroscopic guiding technologies are discussed. Finally, we suggest further improvements that can be implemented by both the physicians and the industry in the future. We are confident that these suggestions are able to reduce patient and operator exposure by more than an order of magnitude, and therefore think that these recommendations are worth reading and implementing by any electrophysiological operator in the field.

Cardiac Resynchronization Therapy Device Implantation Using a New Sensor-Based Navigation System

Background—

Cardiac resynchronization therapy (CRT) device implantation can be challenging, time consuming, and fluoroscopy intense. To facilitate left ventricular lead placement, a novel sensor-based electromagnetic tracking system (MediGuide Technology [MGT], St. Jude Medical) has been developed. We report the results of the First Human Use study evaluating the feasibility, safety, and performance of a novel CRT implantation approach using electromagnetic trackable operation equipment.

Methods and Results—

Fifteen consecutive patients (66±8 years, 53% male) with an established indication for CRT were implanted using the new tracking technology. Demographics, anatomical information, detailed fluoroscopy need, procedure time, and adverse events were collected. Patients were followed up for 4 weeks after implantation. The CRT system was successfully implanted with a lateral or posterolateral left ventricular lead position in all patients. The total procedure time was 116±43 minutes, the median total fluoroscopy time (skin to skin) was 5.2 (Q1–Q3, 3.0–8.4) minutes, and the median fluoroscopy time for left ventricular lead deployment (coronary sinus [CS] cannulation to withdrawal of CS sheath) measured 2.6 (Q1–Q3, 1.6–5.6) minutes. There were no severe complications that required an acute intervention or reoperation during the perioperative and postoperative periods.

Conclusions—

Use of the MGT tracking technology allows for safe and successful CRT implantation with the potential for reduced fluoroscopy time. Future randomized studies are needed to validate these data.

Clinical Trial Registration—

URL http://www.clinicaltrials.gov . Unique identifier: NCT01519739.